1. Field of the Invention
This invention relates to mobile unit navigation and in particular to a mobile unit navigation system and a mobile unit navigation method having a function of learning a differential route between the move route of a mobile unit and the guide route and applying the learn result to the guide route.
2. Description of the Related Art
In a mobile unit navigation system in a related art, the current position of a mobile unit is detected using the GPS (Global Positioning System), etc., and a destination is entered, whereby a search is made for the shortest route from the current position to the destination and the driver is guided with map display or voice, thereby attempting to realize a comfortable move of the mobile unit.
Several arts are shown for reflecting the actual move path of a mobile unit on searching for a guide route so as to provide the user with the optimum guide route to the destination as much as possible. For example, JP-A-9-287969 describes an art of storing the run paths of a vehicle and making a route search with the more frequently applied run path taking precedence over any other run path in a navigation system for a vehicle disclosed in JP-A-9-287969.
However, in the navigation system in the related art, the run path is applied to the guide route with the search cost suppressed for the run path and thus the necessary run path is not necessarily applied to the guide route depending on the setup search cost or conversely an unnecessary run path is applied, etc., namely, the user is guided along the route not intended by the user; this is a problem.
Since all run paths are registered, the capacity of storage means for storing the run paths becomes enormous and the system becomes expensive; this is also a problem.
It is therefore an object of the invention to provide a mobile unit navigation system and a mobile unit navigation method for learning a differential route between the move route of a mobile unit and the guide route and applying the learn result to the guide route, whereby the practical guide route fitted to the user""s taste can be provided.
To the end, according to the invention, there is provided a mobile unit navigation system comprising position detection means for detecting the current position of a mobile unit, map information acquisition means for acquiring map information from a storage medium or an external system, input means for specifying a destination, route search means for searching for a guide route from the current position to the destination based on the map information, and output means for displaying the found guide route as an image or guiding a user along the found guide route with voice, wherein the route search means comprises move route extraction means for extracting a move route of the mobile unit based on a move path of the mobile unit provided by the position detection means and the map information, differential route registration means for extracting a differential route different from the guide route from the extracted move route and registering the differential route, and differential route application means for applying the registered differential route to searching for the guide route.
In the mobile unit navigation system according to the invention, the move route extraction means comprises correction means, if the extracted move route contains a discontinuous part, for correcting the move route to a continuous move route by complementing the discontinuous part based on the peripheral map information.
In the mobile unit navigation system according to the invention, the differential route is a continuous link chain.
In the mobile unit navigation system according to the invention, the differential route application means replaces a part of the guide route with the differential route.
In the mobile unit navigation system according to the invention, if the start point and the end point of the differential route are contained on the guide route, the differential route application means replaces the corresponding portion of the guide route from the start point to the end point with the differential route.
In the mobile unit navigation system according to the invention, the differential route registration means registers each differential route to which additional information indicating the attribute and history of the differential route is added.
In the mobile unit navigation system according to the invention, the additional information contains any of the following or any combination thereof:
1) Registration date and time of differential route;
2) move date and time of mobile unit on differential route;
3) number of times mobile unit has been moved on differential route;
4) move direction of mobile unit on differential route;
5) required time for mobile unit to pass through differential route;
6) passage speed of mobile unit on differential route;
7) position and direction of differential route;
8) route length of differential route;
9) road width of differential route;
10) number of lanes of differential route;
11) inclination degree of differential route;
12) pavement percentage of differential route;
13) open date of differential route;
14) toll required for differential route;
15) limited speed on differential route;
16) limited height on differential route;
17) limited weight on differential route;
18) traffic control on differential route (number of lanes, travel in one direction only, chain, etc.,) and period and times of traffic control;
19) duplication degree with other differential routes; and
20) number of times differential route has been applied to guide route.
In the mobile unit navigation system according to the invention, the differential route application means comprises priority determination means for determining priority of each differential route based on the additional information and applies the differential route to searching for a guide route based on the determined priority.
In the mobile unit navigation system according to the invention, the differential route application means comprises differential route deletion means for deleting an unnecessary differential route based on the priority thereof.
In the mobile unit navigation system according to the invention, the differential route application means comprises application determination means for determining whether or not application of a differential route to a guide route is required.
In the mobile unit navigation system according to the invention, the application determination means determines whether or not application of a differential route to a guide route is required based on the positional relationship between the current position of the mobile unit and the destination.
The mobile unit navigation system according to the invention further comprises road traffic information acquisition means for acquiring road traffic information from an external system, wherein the application determination means determines whether or not application of a differential route to a guide route is required based on the road traffic information concerning the differential route.
In the mobile unit navigation system according to the invention, the input means comprises application condition input means entering an application condition of a differential route to a guide route and the application determination means determines whether or not application of the differential route to the guide route is required based on the entered application condition.
In the mobile unit navigation system according to the invention, the differential route application means comprises application determination means for determining whether or not application of a differential route to a guide route is required and the application determination means determines whether or not application of the differential route to the guide route is required based on the priority of the differential route.
In the mobile unit navigation system according to the invention, the output means comprises discriminate output means for discriminately displaying each differential route registered by the differential route registration means or each differential route applied to a guide route as an image or guiding the use along the discriminated differential route with voice.
In the mobile unit navigation system according to the invention, when the current position of the mobile unit exists in the proximity of an entry point into the differential route applied to the guide route or in the proximity on the differential route, the discriminate output means discriminately displays the differential route as an image or guiding the use along the discriminated differential route with voice.
In the mobile unit navigation system according to the invention, the input means comprises discriminate information input means for adding discriminate information to additional information to each differential route registered by the differential route registration means.
In the mobile unit navigation system according to the invention, the discriminate information contains the identification name or identification number of each differential route or information indicating whether or not application of each differential route to a guide route is required.
According to the invention, there is provided a mobile unit navigation method comprising the position detection step of detecting the current position of a mobile unit, the map information acquisition step of acquiring map information from a storage medium or an external system, the input step of specifying a destination, the route search step of searching for a guide route from the current position to the destination based on the map information, and the output step of displaying the found guide route or guiding a user along the found guide route with voice, wherein the route search step comprises the move route extraction step of extracting a move route of the mobile unit based on a move path of the mobile unit provided by the position detection step and the map information, the differential route registration step of extracting a differential route different from the guide route from the extracted move route and registering the differential route, and the differential route application step of applying the registered differential route to searching for the guide route.